In a move to establish its rising assertiveness on the East China Sea, China has reacted sharply to remarks made by US President-elect Joe Biden on the US commitment to helping Japan defend the Senkaku Islands.

Japanese Prime Minister Suga Yoshihide and Biden had agreed to further strengthen the Japan-US alliance in their first telephone conversation on Thursday. Speaking to reporters, China’s Foreign Ministry spokesperson Wang Wenbin reiterated his government’s position, claiming that the islands are inherently Chinese territory.

He further termed the two countries not to hurt the interests of third parties as well as endanger peace and stability in the region. Suga had said that Biden expressed Washington’s commitment to applying Article Five of the Japan-US Security Treaty to the Senkaku Islands. According to reports, Japan controls the islands, while China and Taiwan lay claim on them. The Japanese government maintains the islands are an inherent part of Japan’s territory, in terms of history and international law. It says there is no issue of sovereignty to be resolved over them.